Parental acceptance of vaccines has eroded and more parents are claiming nonmedical exemptions from school-entry immunization laws. The resultant under-immunization of children has contributed to the persistence of vaccine-preventable diseases that kill 300 children annually. Pediatric health care providers have a critical influence on parental immunization decision-making and play an important role in improving and sustaining childhood immunization rates. The long-term objective of the candidate, Doug Opel, MD, MPH, is to improve childhood vaccination rates through better provider-parent communication. This goal is consistent with the Institute of Medicine objective to sustain and improve immunization coverage rates as well as the US Department of Health and Human Services Healthy People 2020 proposed objective to increase the proportion of persons who report that their health care provider has satisfactory communication skills. To achieve this objective, Dr. Opel will pursue formal coursework, directed learning, and experiential training to improve knowledge and skills in three specific areas: (1) the design, data collection, and analysis of research on provider-parent communication; (2) the scientific, social, political, economic and regulatory aspects of vaccine development and administration; and (3) behavior change theory and approaches to the design of an intervention to improve provider-parent communication. Dr. Opel has identified a primary mentor with expertise in immunization research (Dr. James Taylor) and 3 co-mentors with experience and proficiency in research in provider-patient communication, health services, and bioethics (Drs. Thomas Gallagher, Rita Mangione-Smith, and Diane Martin). All are based in Seattle at the University of Washington. Dr. Opel will meet with Dr. Taylor weekly to ensure adequate contact and with all 4 of my mentors together monthly so they can assess and support my progress. Additional mentoring will be provided by 8 consultants with methodological or topical expertise relevant to the proposed research plan, including pediatric infectious disease, biostatistics, bioethics, behavioral science, and the use of the qualitative technique of conversation analysis to study provider-parent communication. Dr. Opel proposes three innovative and sequential projects in this application that build upon his training goals. Each project will contribute to an improved understanding of specific and modifiable provider immunization communication behaviors that are both effective in increasing parental acceptance of childhood immunizations and can be targeted as part of a future communication-based intervention for providers. The specific aims of this proposal are to: (1) characterize key provider immunization communication behaviors during pediatric health supervision visits with vaccine-hesitant parents; (2) develop and evaluate the validity of a parent self-report instrument in identifying provider immunization communication behaviors; and (3) conduct a longitudinal prospective cohort study of vaccine-hesitant parents to determine whether identified provider communication behaviors predict parental immunization acceptance over time. This proposal is novel because it involves the application of videotape methodology to a new area of health communication research, the exploration of provider communication behaviors over time and not just during a single encounter, and the use of a clinically relevant outcome-a child's immunization status-to determine what constitutes effective communication. The excellent research environments provided by Seattle Children's Research Institute and the University of Washington, as well as Dr. Opel's strong, existing relationships with 2 sites at which recruitment and data collection will occur-Group Health Cooperative and the practice-based research network, Puget Sound Pediatric Research Network-will enhance his training and facilitate his project goals. Dr. Opel is a general pediatrician with training in health services research and bioethics. He has published 7 papers in the last 2 years on the topics of childhood immunization, communication, and bioethics and has secured several grants and contracts to begin the development of a research program aimed at decreasing parental childhood immunization refusal rates by improving provider-parent communication. This award would allow Dr. Opel to focus almost exclusively on his training and research related to improving provider-parent communication and to commit at least 75% of full-time professional effort to his career development program and activities. In addition, it would prepare him to pursue funding as part of an R01 award to conduct a randomized controlled trial of a communication-based intervention for providers to increase their use of effective communication behaviors with vaccine-hesitant parents.